Press for forming tubes.



Ne. 652,637. Patented lune 26, I900.

H. N. POTTER.

PRESS FOR FORMING TUBES.

(Application filed Aug. 14, 1899.)

(No Model.)

NITE rrns ATENT urine.

HENRY NOEL POTTER, OF GGTTINGEN, GERMANY, ASSIGNOR TO GEORGE .XVESTINGHOUSE, OF PITTSBURG, PENNSYLVANIA.

PRESS FOR FORMING TUBES.

SPECIFICATION forming part of Letters Patent No. 652,637, dated June 26, 1900.

Application filed August 14, 1899. Serial No. 727,149. (No model.)

To ctZZ whom, it may concern:

Be it known that I, HENRY NOEL POTTER, a citizen of the United States of America, residing in Gottingen, Germany, have invented certain new and useful Improvements in Presses for Forming Tubes, of which the following is a specification.

In handling the materials which enter into the composition of glowers for lamps of the Nernst class with the object of constructing such glowers in tubular form I have been led to make improvements in the apparatus for manufacturing the tubular bodies from pasty material, and these improvements form the subject of the present invention. When tubular bodies are used as the glowers of electric lamps and are subjected'to the great heat necessary in order to maintain a state of incandescence, it is essential that such bodies should be perfectly even and uniform in their,

structure. Otherwise the walls are likely to collapse and the glowers to be destroyed. When I attempted to make tubular glowers by the known process of manufacturing tubes from pasty matter, I found great difficulty in securing uniformity of structure throughout the tubes owing to the fact that the pasty matter is forced through a series of passages leading to the former by the pressure of a single piston. The trouble with this process resides in the circumstance that if one of the passages becomes clogged in any way the feeding through that passage will be completely or partially obstructed, and consequently the tube on that side will lack material and be thinner than the rest of the tube. In some cases when such obstruction arises the excess in the speed of feeding on the unobstructed sides will cause the tubular structure to be bent to one side and will result in the breaking of the tube. In order to meet the requirements of uniformity in the operation of an apparatus of this sort, I have constructed a mechanism in which the paste is fed to the former by a piston in each passage, and I find that it is easily possible by these means to produce a perfectly-uniform tube amply adequate to meet the very serious conditions which arise in the use of electricmore serious and exacting than those which would apply to almost any other form of tubular structure; but the invention is applicable to any and all tubes made from pasty material. I have myself made use of the same sort of apparatus for producing tubes of talcite designed to constitute the heaterbody in electrical heaters, such as are employed in this kind of lamp.

My invention is illustrated in the accompanying drawings, in which- Figure 1 is a central vertical section of my improved press for forming tubes from pasty material. Fig. 2 is a bottom view of the body of the press. Fig. 3 is a bottom view of a disk constituting a part of the former of my apparatus, and Fig. 4c is a bottom view of a nut which holds the disk in place.

In the drawings, A is a cylinder having at its top a chamber a, large enough to admit the plunger 13 of the press, and also having in its lower half a series of vertical passages h I), designed to receive the pasty material. Below the plunger 13 depend individual pistons c c, which enter the passages b b and press upon the pasty matter inside the said passages. A button d is screwed to the bottom of the cylinder A at its center, and this button is adapted to constitute a core around which the tube of pasty material is formed. Cooperating with the said core is a disk e, having a central opening which surrounds the core (2 and is adjustable with relation to it, whereby it is made possible to bring the said core exactly into the center of the opening in the disk. For holding the said disk in position after adjustment I provide a nut f, with an internal screw-thread at the top which engages with a corresponding screwthread on the lower end of the cylinder A. The adjustment of the disk 6 takes place after the nut f has been screwed nearly tight upon the lower end of the cylinder, after which the nut is firmly tightened. For making it still surer that the disk 6 shall move after being properly adjusted, screws 9 g are passed through the lower end of r the nut f. These screws bear against the lower sides of the disk e and assist materially in holding it to its work.

At the lower end of the cylinder A are grooves h h, which form a means of commu= nication between the lower end of the passages b b and the central opening in the disk 6. It is through these grooves that the pasty material passes from all the passages 19 b to the former, which is made up of the core d and the inner walls of the disk 6. Thus it will be seen that there is a direct pressure from a separate piston upon the pasty matter in each one of the passages of my press, and it is made practically certain that the material will be fed evenly-to the former. In certain cases it is advantageous to have the grooves leading to the former out in the disk instead of in the cylinder, as in this way by the use of extra disks a variety of sizes and thickness of tubes can be pressed with the same press-body.

In the foregoing I have considered the requirements of a press for squirting tubes of uniform wall thicknesses and strength. Owing, however, to the peculiar construction of my press each small area of the cross-section of the tube is squirted practically independent of the adjoining sections. If, therefore, it be desired to squirt tubes having the wall thicker at one part than another of the crosssection, it is merely necessary to design the press so that the cylinder or cylinders feeding to the thick portion of the wall may be proportionately larger in area than those that feed to the thin portion.

Theidea of feeding separately to a plurality of sections of the completed tube can be eX- tended to presses for squirting ribbon, crescents, star forms, crosses, and other complicated cross-sections without wrinkles,tearing, or any of the troubles experienced with singlepiston presses. A further interesting varia tion is produced by making certain of the cylinders feed m ore rapidly than the others by giving them a greater piston area or in other ways. In this way a predetermined and fixed irregularity of feed is secured. If now a tube of uniform wall thickness or other section be squirted with such a press, various shapes will be produced, depending on the greatness and arrangement of the irregularities. With such presses it is possible to squirt spiral tubes and such as have ripples latitudinally at certain places and to do a variety of curious and useful things not possible with other presses.

I claim as my invention 1. In a press for forming tubes from pasty materials, a die composed of a central core or button, and a disk, having an opening surrounding the said core so as to leave an intermediate space, a nut holding the said disk in place and two or more screws pressing against the bottomof the said disk.

2. In a press for forming tubes from pasty.

material, a cylindrical body, having separate passages therein for containing pasty material, 37001'6 orbutton secured to the end of the said cylindrical body, and grooves or channels leading thereto, a disk cooperating with the said core or button to constitute a die or former, the said disk being provided with an opening surrounding the said core so as to leave an intermediate space, the lower end of the said cylindrical body being screw-threaded, a nut for holding the disk in place, in combination with additional devices, such as screws, for insuring the stability of the disk under pressure.

3. In a press for forming tubes from pasty material, a cylindrical body having an opening, a plunger within the said opening, a number of pistons connected with the said plunger, and separate passages or cylinders in the lower part of the cylindrical body, the said passages communicating with grooves or channels on the lower end of the cylinder, in combination with a button or core secured to the lower end of the cylinder, a disk having an opening which surrounds the said button or core so as to leave an intermediate space, and suitable clamping devices for the said disk.

Signed by me at Hanover, Germany, this 14th day of July, 1899.

HENRY NOEL POTTER.

Witnesses:

W. K. ANDERSON, KIRKE LATHROP. 

